The c-Met protein (hepatocyte growth factor receptor: HGFR, hereinafter referred to as “c-Met”) is a receptor tyrosine kinase and is known as a receptor for a hepatocyte growth factor (HGF). c-Met is a heterodimer membrane protein composed of an α chain and a β chain, and the β chain is composed of a tyrosine kinase domain, a membrane-spanning domain, and an extracellular domain. When HGF binds to the extracellular domain of c-Met, the tyrosine kinase domain is phosphorylated, whereby the signal transduction system is activated. By this activation of the signal transduction system, cell proliferation, cell infiltration, cell movement, etc. are controlled, for example.
It has been reported that overexpression of c-Met is seen in cancer cells of many tissues such as the liver, kidney, pancreas, lung, bladder, prostate, seminal vesicle, ovary, breast, mammary gland, and digestive tracts such as the stomach and colon (Non-Patent Document 1). Thus, c-Met is attracting attention as a target and a diagnostic marker for diseases including various cancers. Under such circumstances, it has been desired to produce a substance capable of binding to c-Met and to prevent and treat the above diseases by neutralizing the action of c-Met with the substance.